MILWAUKEE (Reuters) - A Wisconsin girl stabbed 19 times in a murder plot allegedly hatched by two classmates to win favor with a fictional Internet character, has been sent a prestigious Purple Heart medal by an anonymous well-wisher, the victim's family said on Tuesday.

The Purple Heart was recently sent to the 12-year-old girl in an unsigned card that read, "The Only Heart I Could Find – Be Strong," the family said in a statement.

"The family has been so touched and moved by this act of kindness that they would like to personally thank the individual, publicly or privately, for the gift and for their sacrifice for our country."

The Purple Heart is awarded to members of the U.S. military who are wounded in battle or posthumously if they are killed in action or die after being wounded in action.

"It does not surprise me that a decorated veteran unselfishly gave this amazingly brave and courageous little girl something from his or her heart," Wisconsin Department of Veterans Affairs Secretary John Scocos said in a statement.

The girl, who has not been identified, was lured into a park and stabbed 19 times in late May in Waukesha, a western suburb of Milwaukee, by two classmates after a sleepover the night before, according to authorities.

The victim spent six days in the hospital after the attack and is now recovering at home, the family recently said.

Her alleged attackers, Morgan Geyser and Anissa Weier, both 12, face up to 60 years in prison if convicted as adults of attempted homicide. They could be incarcerated to age 25 if they are convicted as juveniles under state law.

Weier and Geyser told investigators they stabbed the girl to impress Slenderman, a tall, fictional bogeyman popular on the Internet that they insisted was real, according to a criminal complaint.

Two doctors concluded that Geyser was incompetent to stand trial and a judge ordered a competency hearing on Aug. 1 at the request of prosecutors.